ML20149G242
| ML20149G242 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 02/12/1988 |
| From: | Shawn Smith TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 87-17, NUDOCS 8802180184 | |
| Download: ML20149G242 (4) | |
Text
r-e TENNEOCEE VALLEY AUTHORITY Sequoyah Nuclear Plant Post Office Box 2000 Soddy-Daisy Tennessee 37379 February 12, 1988 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:
TENNESSEE VALLEY AUTHORITY - SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 - DOCKET NOS. 50-327 AND 50-328 - FACILITY OPERATING LICENSE DPR-77 AND DPR SPECIAL REPORT 87-17 REVISION 1 The enclosed special report revision provides the conclusions of an investigation and a status of corrective actions concerning 11guld releases
-from condensate demineralizer waste system directly to the cooling tower blowdown line while effluents exceeded the 31-day total body projected dose limit. This event is reported in accordance with action statement (a) of Limiting Conditions for Operation 3.11.1.3.
Very truly yours.
TENNESSEE VALLEY AUTHORITY y
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S.2J. SNi[
Plant Manager Enclosure cc (Enclosure):
J. Nelson Grace Regional Administrator U. S. Nuclear Regulatory Commission Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323 Records Center Institute of Nuclear Power Operations Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 NRC Inspector, Sequoyah Nuclear Plant 8802100104 880212 PDR ADOCK 05000327 S
PDR gg An Equal Opportunity Employer
SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 SPECIAL REPORT 87-17 This revision is being submitted to provide the conclusion of the investigation conducted to ensure the high crud tank (HCT) contents are processed through a filter system when making a HCT release to the cooling tower blowdown line or to the 11guld radwaste processing system when projected dose limits are exceeded and to provide a status of corrective actions.
DESCRIPTION OF EVENT On November 5, 1987, with units 1 and 2 in mode 5 (0 percent poser 3 pais, 120 degroes and 0 percent power, 114 psig, 100 degrees F, respectively), it was discovered (via a review of previously performed 11guld effluent dose calculations) that on two occasions, the Technical Specification (TS) Limiting Condition for Operation (LCO) 3.11.1.3 total body projected dose limit we-s exceeded, and releases were made without processing through the radwaste treatment system. TS LCO 3.11.1.3 requires the 11guld radwaste treatment system to be used to reduce the radioactive materials in 11guld wastes before their discharge when the projected doses due to the 11guld effluent to unrestricted areas would exceed 0.06 mrem per unit to the total body or 0.2 arem per unit to any organ in a 31-day period.
In June 1985, radioactive liquid releases were made with a projected dose of 0.14 mrem to the total body, and in July 1985, radioactive 11guld releases were made with a projected dose of 0.17 mrem to the total body. These releases were made from the condensate demineralizer waste systems directly to the cooling tower blowdown line.
In August 1984, a new high crud filter was installed in line between the high crud tanks, which are part of the condensate demineralizer waste system, and the cooling water blowdown line. This was a modification performed to provide a higher flow capacity discharge path necessary to support unit I and unit 2 releases. The postmodification testing had not been completed, and therefore.
l the filter had not been placed in operation. The filter is provided to reduce the suspended solids in a release. The releases mado to the cooling tower blowdown line had been made through a filter bypass line. This is contrary to Final Safety Analysis Report (FSAR) section 11.2 when releasing the high crud tank when the contents are radioactive.
The condensate demineralizer wastes are generated and collected during condensate demineralizer regeneration process. This waste was radioactive due to a steam generator tube leak during the time the regenerated condensate demineralizer bed was in service. The cooling tower blowdown line provides a release path for these wastes. The cooling tower blowdown line discharges to the diffuser pond which is released to the Tenneseee River.
A review of the documentation for actual releases made were within the concentration limits of TS LCO 3.11.1.1 and Appendix B. Table 2, column 2, of 10 CFR 20.
CAUSE OF EVENT The procedure used during the subject releases in 1985 for dose calculations for 11guld effluents Surveillance Instruction (SI)-422.), Revision 0, "Monthly Appendix I Dose Calculations Liquid Effluents") incorrectly stated the projected total body dose limit as 0.5 mrem and the maximum organ projected dose limit as 1.66 mrem.
Since the limits stated in SI-422.1, Revision 0, were not exceeded, a notification was not made to the lead Chemical engineer l
to ensure the 11guld radwaste treatment system would be used during releases.
The high crud filter had not been placed in service because preoperational testing has not been completed, and thus it had not been turned over for operations.
SI-400.1, "Liquid Waste Effluent Batch Release," did not require the high crud filter to be in service when releasing to the cooling tower blowdown line, and thus a filter bypass line had been used when performing l
releases.
The above stated contributing problems are symptoms indicative of a weak program in the past for ensuring complete and accurate commitments / requirements are captured in implementing documents.
ANALYSIS OF EVENT This event is being reported in accordance with the requirements of action statement (a) of TS LCO 3.11.1.3.
Recent samples were taken from the diffuser pond at eight different locations. These samples were analyzed for resin and activity. No resin was c
found in any of the diffuser pond samples. Trace amounts of activity were found in some samples. No diffuser pond samples exceeded 0.51 pC1/g wet for i
any one radioisotope. Samples were also taken from yard pond and the low volume waste treatment pond, which dre not directly released to the Tennessee River, but do receive condensate domineralizer wastes. Resin was found in the yard pond and low volume waste treatment pond. The highest activity found was 4.74 pCi/g wet from Cs-137 in the low volume waste treatment pond.
It was postulated that this activity was deposited on the shoreline diffuser pond with a man standing near it for 365 days. It was calculated that the man would receive approximately 1 mrem to the whole body under this scenario.
This analysis resulted in the conclusion that this event had no significant environmental impact.
CORRECTIVE ACTION SI-422.1 was changed on December 19, 1987, to ensure the shift engineer is notilled when projected dose limits are exceeded so that all condensate demineralizer wastes and radwastes are processed through the 11guld waste processing system. SI-422.1 was revised on October 14, 1986 (revision 2),
which provided the correct limits for total body and maximum organ 31-day projected doses. The limits were changed independent of this occurronce.
A filter system was made available for high crud tank releases on December 29, 198?.
e s.
SI-400.2, "Condensate Demineralizer Waste Effluent to the Turbine Building Sump - periodic Releases," was changed on December 29, 1987, to provide procedural steps for utilizing the filter system or the 11guld radwaste processing system.
SI-400.1 was changed on December 29, 1987, to provide procedural steps for utilizing the filter system or the 11guld radwaste processing system.
System Operating Instruction (SOI)-14.3, "Condensate Domineralizer Waste Disposal," was revised on December 29, 1987, to provide procedural steps for aligning the filter system when releasing the HCT to the cooling tower blowdown line.
An SI review program has been implemented to review survel11ance instructions to ensure they are technically adeguate and in compilance with TS.
The program review for technical adequacy and compilance with TS of procedures has been completed for unit 2.
sis are also subject to periodic reviews, and all SI revisions which implement a TS survelliance requirement will be reviewed to ensure their compliance.
The FSAR section 11.2 will be updated in the Apell 1988 revision to clarify the purpose of the high curd filter and when it is required to be used.
The investigation conducted on this matter concluded that the addition of the l
filter system and the changes made to SI-400.1, SI-400.2, SI-422.1, and SOI-14.3 will procInde HCT releases to the cooling tower blowdown line without placing the high crud filter in service and will ensure that the 11guld radwaste processing system will be used to process wastes when projected dose limits are exceeded.
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